DTC P0504-2B: Brake Switch "A"/"B" Signal Cross Coupled [10/2022 - ]: Procedure

Pre-procedure1

• Disconnect the stop light switch assembly connector.

• Measure the voltage according to the value(s) in the table below.

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  A32-1 (B) - Body ground	Always	11 to 14 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY) 

Result: 

OK 

See step  2

Pre-procedure1

• Disconnect the stop light switch assembly connector.
• Turn the ignition switch to ON.

• Measure the voltage according to the value(s) in the table below.

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  A32-5 (B) - Body ground	Ignition switch ON	11 to 14 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

NG 

See step  6

Result: 

OK 

See step  3

Pre-procedure1

• Disconnect the stop light switch assembly connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  A32-3 (GND) - Body ground	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

Pre-procedure1

• Disconnect the ECM connector.
• Turn the ignition switch to ON.

• Measure the voltage according to the value(s) in the table below.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a	Brake Pedal Depressed	*b	Brake Pedal Released
  *c	Front view of wire harness connector (to ECM)	-	-

  Standard Voltage

  Tester Connection	Brake Pedal Operation	Specified Condition	Result
  A16-13 (ST1-) - Body ground	Released	7.5 to 14 V	V
  A16-13 (ST1-) - Body ground	Depressed	Below 1.5 V	V
  A16-14 (STP) - Body ground	Released	Below 1.5 V	V
  A16-14 (STP) - Body ground	Depressed	7.5 to 14 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

OK 

REPLACE ECM. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

See step  5

Pre-procedure1

• Disconnect the stop light switch assembly connector.
• Disconnect the ECM connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  A32-4 (L) - A16-13 (ST1-)	Always	Below 1 Ω	Ω
  A32-2 (L) - A16-14 (STP)	Always	Below 1 Ω	Ω
  A32-4 (L) or A16-13 (ST1-) - Body ground and other terminals	Always	10 kΩ or higher	kΩ
  A32-2 (L) or A16-14 (STP) - Body ground and other terminals	Always	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

OK 

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Pre-procedure1

• Remove the IGP NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
• Disconnect the stop light switch assembly connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  5 (IGP NO. 1 relay) - A32-5 (B)	Always	Below 1 Ω	Ω
  5 (IGP NO. 1 relay) or A32-5 (B) - Body ground and other terminals	Always	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

OK 

GO TO ECM POWER SOURCE CIRCUIT. Refer to  ECM Power Source Circuit [10/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR